1. Field of the Invention
The present invention relates to a temperature correction processing device for use in a temperature measuring apparatus for measuring temperatures of, for example, human beings or objects by detecting heat ray images of, e.g., far infrared rays irradiated from the human beings or objects. It also related to a temperature measuring apparatus equipped with the temperature correction processing device.
2. Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
As a temperature measuring apparatus, a two-dimensional thermopile array has been used for detecting temperatures of objects to be measured. The two-dimensional thermopile is constituted by a plurality of thermopiles combined lengthwise and crosswise so that the amount of thermal changes in a certain detecting area can be measured. The thermopile is made by combining a plurality of thermocouples to increase the output voltage. For example, conventionally, such a two-dimensional thermopile array has been installed on a ceiling plane of a microwave oven as a temperature measuring apparatus for measuring the temperature of an object to be heated in the microwave oven in a non-contact manner.
Concretely, as disclosed by Japanese Unexamined Laid-open Patent Publication No. 2001-355853, in a microwave oven, a turn table is set as a temperature measuring area of a two-dimensional thermopile array so that the temperature distribution of an object placed on the turn table can be measured by the two-dimensional thermopile array.
The technique using the aforementioned two-dimensional thermopile array can also be applied to a means for detecting existence of a human body. For example, an illuminating lamp having a built-in two-dimensional thermopile array for detecting a human body has been proposed. A thermopile can also be used for detecting occurrence of fire or existence of human bodies based on the thermal change amount. Among other things, in recent years, a thermopile has been greatly expected to be used in fire alarms and/or security devices for detecting, e.g., human bodies (see, e.g., Japanese Unexamined Laid-open Patent Publication No. 2000-223282).
However, the aforementioned background technique had the following drawbacks. That is, the temperature information of an object disposed in the detecting area is obtained by adding the temperature of the thermopile itself to a relative temperature difference between the temperature of the detecting area and that of the thermopile. The temperature of the thermopile itself is detected by a thermistor as a thermal sensor, and the relative temperature difference is detected by the thermopile.
In manufacturing such thermopiles and thermistors, however, manufacturing dispersion may occur, resulting in different characteristics, which in turn may cause measuring errors. Even if thermopiles and thermistors have uniform accuracy, during the assembling steps, errors may occur, which also results in different characteristics. Thus, it was very difficult to obtain a temperature measuring apparatus having measurement accuracy falling within a predetermined range.
Furthermore, if a strict selection test is performed to secure uniform accuracy, a number of products will be deemed as defective products, resulting in an increased sales price. In other words, it was difficult to provide a temperature measuring apparatus with high accuracy at low cost.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. For example, certain features of the preferred embodiments of the invention may be capable of overcoming certain disadvantages and/or providing certain advantages, such as, e.g., disadvantages and/or advantages discussed herein, while retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.